


Omen

by BrightEyesEren



Category: Gravity Falls, 僕のヒーローアカデミア | Boku no Hero Academia | My Hero Academia
Genre: Biting, Blood, Crossover, Demon Bill Cipher, Demon Summoning, M/M, Orgasm Delay/Denial, Plot What Plot/Porn Without Plot, Rough Sex, Semi-Public Sex, Unsafe Sex
Language: English
Status: Completed
Published: 2020-09-21
Updated: 2020-09-21
Packaged: 2021-03-07 16:34:07
Rating: Explicit
Warnings: Graphic Depictions Of Violence, Rape/Non-Con
Chapters: 1
Words: 3,315
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/26580712
Author URL: https://archiveofourown.org/users/BrightEyesEren/pseuds/BrightEyesEren
Summary: Natsuo tries to find a solution to his problems.It seems he's added one more to the list.
Relationships: Bill Cipher/Todoroki Natsuo
Kudos: 11





	Omen

**Author's Note:**

  * For [VirusZeref](https://archiveofourown.org/users/VirusZeref/gifts).



> thank you, Kori !! ;w;

Natsuo’s sure this is going to work.

He’s done his research. He’s weighed out his options. He’s lived a long enough life and endured enough that it won’t be the end of the world if it somehow doesn’t work out.

Carefully, he lights the candles, watching the way each one illuminates the room. Double checks the sigils he drew, takes a deep breath. He draws blood from his wrist and recites the words he spent so long memorising, practicing. By the time he finishes the last sentence, the candles have gone out. Smoke wafts up into the air, leaving the room silent and dark. Natsuo takes a look around the room, but he doesn’t see anything. No new sight, sound, smell.

It didn’t work.

He’s not… sad. Or upset in any way, for that matter. He feels the barest hint of disappointment, but that vanishes before he can feel it truly and deeply. He’s felt far worse before, and he already set himself up for the possibility of failure. He flips his bedroom’s light switch back on, cleans up the mess of materials scattered across his floor, and carries on with his night. It’s not a big deal. Honestly, it was a stupid idea to try summoning a demon.

He goes about the next day normally, the previous night all in the past. He takes the train to the neighbouring city, watches people passing by on his walk to campus, and starts his day of classes. He only has three lectures, all with reasonably sized breaks in between. It’s enough time for him to go from building to building, eat a meal, talk with friends, grab a coffee. It might not look like much of a routine to other people, but it’s what he considers normal.

Before his last lecture, he gets a quick call from Fuyumi. It’s a relatively new routine of theirs, but it’s a welcome one. She asks him how he’s doing, makes sure that his grades are good and that he hasn’t burned down the kitchen yet. Their conversations never last long; still, they give him the push he needs to make it through the rest of the day.

It’s days like this that he’s grateful for what he has. Professors that care about him, friends that love his company, siblings willing to check up on him every now and again despite everything they’ve gone through.

Natsuo makes one last stop before heading home. One of the classrooms, just on the other side of campus. It’s a bit out of his way, but a little extra walking never hurts.

He left a notebook in that room earlier. Peering into the window, it seems like no one’s there. Perfect. The door is unlocked, so Natsuo walks in and looks around a bit. His notebook was left on a table in the back. He picks it up, puts it in his bag, and starts walking back towards the door. He can buy himself some dinner, go home, and-

Someone swings open the door. It startles him.

“Well, well, well. What do we have here?” The stranger greets him with a smile.

“Hey there…? I was picking up a notebook I left earlier.” Natsuo takes a step back. The man is staring at him, but Natsuo can’t read the expression on his face. Natsuo’s never seen him before. Maybe he was one of his classmates; he didn’t always remember the faces of everyone around him. Though, he’s sure he would remember someone so distinct.

Bright blonde—no, yellow—hair, an eyepatch? He’s strange. His appearance, his demeanour, all of it. Natsuo tries not to stare for too long; he’s a bit unsettling. Something in Natsuo’s head is telling him that he’s a villain, that he should leave before things escalate, but the stranger speaks up.

“How are you?” He asks. It’s nothing more than a polite question, but it leaves Natsuo even more worried.

“I’m… doing well, but I should get going,” Natsuo says with a forced smile, “It was nice meeting you.”

The stranger stops him from leaving the room. He stands in front of the door and stares at him with an expecting gaze.

“Are you going to abandon me, snowflake? After all of your efforts to bring me here?”

“I don’t know what you’re talking about.” Natsuo tries to push past him, but he’s still blocked by the stranger.

“What? You don’t remember your little ritual from last night, with the candles and the chanting and everything? It was quite the extravagant set-up. You made me feel so _special._ ”

Suddenly, Natsuo’s blood runs cold. It’s not clicking in his head quite yet. He doesn’t want to believe it. He failed last night, and nothing came of his efforts. He checked, searching every corner of his room for a sign that it worked. This stranger is messing with him, and that’s it. It’s a joke with some oddly specific details.

Natsuo tries to push past him, but he’s stopped again, this time with a hand against his chest. The stranger grins, and Natsuo’s horrified to see the sharp teeth in his mouth.

“Maybe I should’ve introduced myself first,” He purrs out those few words, low and taunting. Somehow, that’s been the most terrifying thing to happen so far. “The name is Bill Cipher. It’s a pleasure to meet you, Natsuo.”

“H-how the hell do you know my name?”

“Did you really forget that much of the ritual you studied oh so closely? I’m offended, darling.” Bill rests a hand over his heart and clicks his tongue. He rolls his eyes and closes the remaining, tiny bit of distance between them. “I want you to think back over what you said to bring me into this world.”

Natsuo can’t think that far back. His brain wants him to run away while he has the chance, but he’s stuck there, Bill inches away from him. Natsuo watches the tail that snakes out from behind him, the horns that curl out of his skull. He notices that his pupil is a slit now that they’re this close. Natsuo’s eyes flick back to the pointed teeth in his mouth, and—

He decides he wants to run _now_ . He doesn’t want to be trapped in a room with this _monster._ There aren’t any other doors or windows in here. It would be pointless to go to another side of the room, when Bill could simply follow him. He falls onto the sick realisation that Bill is likely stronger, faster than he is, capable of far more than Natsuo is. It’s exactly what he asked for, but he wouldn’t stand a chance in a fight with his quirk. There’s not another way out of this mess.

With a shaky breath, Natsuo takes a couple small steps back. There’s a bit of distance between them now, but it’s not nearly enough to ease his discomfort.

Bill hums, making a show out of looking between the door and Natsuo, twirling in place. He stops and faces Natsuo, the grin on his face toothy and proud.

“Are you done trying to escape? If so, I think it’s alright if we have a little bit of fun here. Only because I can’t wait any longer. I’ve been so _excited_ , snowflake.”

The way Bill says it makes Natsuo’s stomach churn. He knows what he’s implying, but… no. He can’t. He shakes his head and takes another step back, heart pounding harder and louder the closer Bill gets to him.

“No way. I don’t want you. I’m not l-”

Natsuo’s pleas are cut off the moment Bill kisses him. It starts off almost timid, shy, but that’s nothing more than a façade. The demon’s tongue is in his mouth before he can protest. Natsuo pulls away and takes a few more hurried steps back, until he bumps into a table, nearly knocking it over.

He wishes he didn’t hit into it. Bill takes it as an opportunity to take hold of him, restrain him with far more force than Natsuo thought he would. The panic far outweighs the fear in his mind and the pain of Bill gripping the wound on his wrist. No amount of adrenaline is getting him out of this one. He hears his heartbeat in his ears.

Bill rolls their hips together, forcing a moan from his throat. He feels his face flush with heat and embarrassment.

“Were you lying to me earlier? It doesn’t seem like you hate this so much. Maybe you wanted me after all?” Bill chuckles, and the sound sends shivers down his spine. He lets go of one of Natsuo’s wrists.

Natsuo tries to stop him from unzipping his jeans, but his hand is smacked away. He’s not sure he wants to keep fighting back. As much as he wants to get out of this, he doesn’t want to worsen his situation. Only way to survive is to go along with it, right?

It’s easier said than done, though. His eyes flicker back and forth between Bill and the door, the anxiety almost as strong as the sudden and growing arousal. He can’t focus on what’s happening, so caught up on the thought of someone walking in on this scene. There would be no excuse, no lie that could cover this up.

“Eyes on me, angel.”

Natsuo moves his eyes back to Bill. He doesn’t want to watch this, but he finds himself unable to look away again. There’s no one else here, and no one’s opening the door at this very moment. He can watch Bill, follow his request. It’s better that he listens.

The demon waits to make sure Natsuo’s holding eye contact, then runs his tongue along the underside of his cock. Natsuo stifles a moan, putting a hand over his mouth. This is wrong.

He tries his best to keep himself silent. It’s unnerving having Bill stare up at him expectantly, waiting for the moment Natsuo slips. He can’t smile with his mouth full, but Natsuo imagines he would be grinning if he could.

Of course his body reacts to this. His cock twitches in Bill’s mouth, and he can feel the demon laugh, the muted sound sending vibrations along his cock.

Bill pulls off of him and stands back up, licking his lips.

“I can’t have you coming for me so soon. Turn around for me, sweetie.”

Natsuo stays exactly where he is. He glances towards the door again, contemplating. He can’t put any of his thoughts to good use; Bill grabs him, turning his body towards the table he was leaning against seconds before.

He’s pushed forward, and his hands catch his body before he slams his face into the table. Before he can ask Bill what the hell he’s doing, his pants are pulled down to his knees. He wants to stop this, rearrange his clothes, leave as soon as he can, but Bill keeps him in place. It doesn’t matter how much he struggles. Bill’s fingers still find their way into his ass, prying him open.

The stretch _hurts;_ it’s impossible to relax. He braces the table and tries to even his breaths, pull himself into the steady rhythm of an inhale and exhale. The pain is suffocating, constricts him to the core, but he knows there’s worse to come. His lungs need to cooperate, prepare.

“Why are you trying so hard to resist me?” Bill taunts, “Did you make a mistake summoning me?”

Natsuo isn’t given the breath to respond. Bill forces his cock in and steals the air from his lungs. Natsuo lets out a noise, but he’s not so sure what it is. A moan? A yelp? Something pained and pleased and _conflicted._ And still, he doesn’t push Bill away. He can’t; he needs to bear it. He feels stretched and full—way too _full_ —like he couldn’t possibly handle anything more.

He lets Bill fuck him, brutal and fast. Natsuo isn’t allowed to prepare for this. He brought Bill here in the first place, and he’s stuck facing the consequences. Bill’s hands are gripping his hips far too hard for comfort. He knows it’ll bruise later, leave behind dark purple handprints as a reminder of what he put himself through.

Natsuo’s terrified. He doesn’t want someone to walk in, see him getting fucked senseless by a demon he didn’t know he summoned the night before.

His demon doesn’t let him breathe. It’s like fire in his lungs, burning up every ounce of oxygen and destroying even the slightest bit of motivation to push Bill off of him.

It feels good.

He doesn’t want it to feel good.

_It feels so good._ He wants more, his body going lax, his hips rolling back to meet each thrust. He can’t name the last time he’s enjoyed himself this way. There’s still a part of him that screams in horror and protest, that tells him he shouldn’t like this as much as he does. That he shouldn’t like this at all. Bill is a _demon,_ and they could be caught at any moment—but maybe it’s part of the fun.

Giving into the sensation is easier. He lets himself get lost in the bliss. He succumbs to the heat, the intensity. It gives him the room to moan, to let his hesitant pleasure be known.

“Bill, I’m close…!”

“Who said you were allowed to come?”

He feels a hand squeeze the base of his cock, and he can’t hold back the sob that leaves his mouth. He wants to come already. Partly to get this over with, partly because he wants the _release._ There’s a desire to feel good, to orgasm, to prove to Bill that summoning him wasn’t a mistake. He wants to take control back.

Bill slows the roll of his hips, bringing Natsuo down from the high he was building. With that comes the sensation of tears pricking at the corners of his eyes, a lump swelling in his throat, an overwhelming urge to cry out. And worst of all, he hears an inhuman sound in his ear, something akin to a snarl. 

“What are you-”

Bill’s teeth rip into his shoulder. It takes all his power to not scream and alert someone passing by outside the room. Instead, he lets out a shuddering breath, the tears he was holding back rolling down his cheeks. He feels the blood pool and spill, running across his skin and dripping down his arm. It falls onto the table he’s been bracing, a splatter of bright red he can’t tear his eyes away from.

He bites down on his lower lip hard enough to taste his own blood. Deep breaths. In and out. They’re unsteady, each one accentuated by Bill’s relentless thrusts into him. Counting each inhale keeps him from crying out.

Behind him, Bill mutters something about how good Natsuo tastes, but the words barely register in his mind. It’s the last thing he can focus on right now, between the splitting pain in his right shoulder and the almost unbearable level of arousal overtaking his entire body.

“Bill, I’m- let me come.”

“Sorry, I don’t think I heard you, snowflake.” He thrusts harder into Natsuo to prove his point. Natsuo almost chokes on his breath. He needs a minute before trying again, gripping the table underneath hard enough that his knuckles turn white. The burn coursing through his body is no longer from arousal; it’s a lack of oxygen, the searing pain of breathlessness catching up to him. He forces out the one word on his mind.

_“Please.”_

“Oh? I didn’t think I would get you to use your manners.” The laugh Bill lets out is nothing short of cruel. There’s no indication that he’ll let Natsuo get what he wants.

He feels those teeth tear back into his shoulder. It hurts. It’s electricity, shooting up his neck and down his arm. Bill moans, loud and unabashed, the sound echoing through his ear, through the classroom they’re fucking in. The sound of his desire masks the noise of his flesh being ripped into.

He’s overwhelmed. He can’t think straight. Natsuo’s dizzy with pleasure, with pain, with blood loss.

There’s a new pain that follows. The same, sharp ripping, into his hips this time. He can see stars in his vision, the edges of his mind going blank. _Claws._ Nails long and sharp, like daggers, tearing apart his flesh. He feels the blood trickle down his thighs, stopping to soak into the fabric of his pants.

Natsuo finally comes with a sob. Bill doesn’t halt his hips, riding out his own orgasm before pulling out of him. Natsuo slumps over the table and tries to catch his breath, his entire body drained. He feels warm liquid leak down his inner thighs, different from his blood.

“Now, now, no need to cry.” Bill coos. He brushes the tears off of Natsuo’s cheeks with a grin. When a few more run down his face, Bill leans forward and licks them off, moaning at the taste before pulling away. He makes no effort to help Natsuo up from the table. It takes every ounce of his remaining energy to stand up straight, not even bothering to pull up his pants quite yet.

He feels wrecked. Used. He wants to say something, _anything_ to Bill about what just happened, but he can’t come up with the words for it.

But through his half-consciousness, Bill read his mind.

“You summoned me for a reason. There’s no turning back now, snowflake.”

“I can find a way to- to-”

“To _what?_ You knew exactly what you were doing bringing me here. You can’t undo this.”

His mind scrambles to prove Bill wrong. There has to be a way, right? He spent weeks and weeks researching this, finding a way to finally summon something that could keep him and his family safe from his father. It couldn’t have backfired after all the effort he put in to make sure it was going to be okay. This is the alternative, the way up and out of his situation, the thing that’s supposed to make his life so much better than it is now.

He was supposed to show his sister that it worked out. She would’ve been so happy to see a solution he came up with himself. His siblings were supposed to be proud of him.

Now he’s not so sure how it was supposed to work. Was he so foolish that he thought summoning a demon would fix his problems? He shouldn’t blame Bill for the hole he dug himself into.

“I’m not hearing much of a response. Beating yourself up about it in there?” Bill taps a finger on his forehead, letting out a laugh that almost brings Natsuo to tears all over again. It does, however, bring him down his knees.

“No, of course not.”

“No?” Bill echoes, “I think that’s a lie.” He kneels down to Natsuo’s level, resting a hand on his cheek with a smile. The contact makes him shudder. He wants to pull away, but his body refuses to give him the strength. Bill kisses his forehead and finally, he gives in to the urge to start crying again.

The classroom is quiet, with the exception of his sniffles. No one walks by the classroom. No one to see the aftermath of his shameful encounter, no one to save him from the demon he’s bound to. He feels weak. Useless. The smile Bill wears only makes it worse.

“Fuck you.” Natsuo manages. It doesn’t even begin to cover everything going through his head.

Bill _laughs._ He finds joy in this. He looks thrilled that Natsuo’s struggling to stay conscious. Happy to have him bleeding and broken, almost humiliated. It makes him sick.

“Just remember, angel,” Bill leans in close, his hands gripping Natsuo’s hips, “You’re _mine.”_

**Author's Note:**

> this was a ride to write aha. ^^ hope you enjoyed it ! <3


End file.
